We are trying to send an invoice from quickbooks through Outlook 2007, and some of the people have emailed me back saying that they are getting the attachment as a winmail.dat file instead of the usual pdf. This is not happening to everyone i send this to though, I have tried the solution of following these steps off microsoft's support site and nothing has helped
Tools > Options > Mail Format tab > Internet Format. The default is to
> convert to HTML
This option is within outlook. So I'm trying to find a different solution to send my .pdf files through outlook.